Diabetes is a lifelong condition and is characterized by the inability of the body to produce or respond to insulin in order to maintain blood glucose levels. Glucose, a sugar carried by the blood that is produced from food a person eats, is one source of the body's energy. In order for a person's cells to use glucose, their pancreas, which is a gland behind the stomach, produces insulin which is needed to move the glucose from blood into cells. When the pancreas stops making enough insulin, the cells can't use glucose and it builds up in the blood or in urine. In diabetes, other sources of energy must be used, which may lead to many health problems, including atherosclerosis and heart disease. Type 2 Diabetes Mellitus, also known as non-insulin dependent diabetes mellitus (NIDDM), or adult (late)-onset diabetes, is the most common type of diabetes. In the US, close to eight million people are diagnosed with Type 2 Diabetes and it usually afflicts people over 40 years of age. Half of Type 2 diabetes do not notice any symptoms. In this type of diabetes, the body produces insulin but is unable to use it. Some people with Type 2 Diabetes can maintain a normal level of glucose in the blood through exercise and diet. However, diet and exercise therapy alone are not successful in controlling levels of glucose in the blood in the majority of Type 2 diabetes. For these people, use of medication is appropriate. Therefore, this research study was designed to test whether control of blood sugar improves the function of blood vessels as measured by vasodilation (expansion) of a blood vessel in the arm called the brachial artery. The study also tests whether normal levels of glucose in the blood can be maintained by two different treatments in accordance with the recommendations set out by the American Diabetes Association.